PAlbociclib Plus Tamoxifen for the Treatment of Hormone Receptor-positive, HER2-negative Advanced Breast Cancer Women - Asian studY

Asian, International, Multicenter, Randomized, Double-Blind, Placebo-Controlled, Phase 3 Trial of Tamoxifen With or Without Palbociclib ± Goserelin in Women With Hormone Receptor-Positive, HER2-Negative Advanced or Metastatic Breast Cancer

This study is conducted to evaluate the benefit of adding palbociclib in hormone receptor (HR)-positive, HER2-negative advanced or metastatic breast cancer patients, regardless of menopausal status, treated with tamoxifen (with or without goserelin) versus tamoxifen alone (with or without goserelin).

Inclusion Criteria:

• Women 18 years of age or older with histologically or cytologically proven locally advanced or metastatic breast cancer, not amenable to resection or radiation therapy with curative intent
• Documented diagnosis of HR+/HER2- breast cancer
• Any menopausal status
• Previously untreated with any endocrine therapy for their HR+/HER2- advanced breast cancer; or progressed while on or within 3 month from prior endocrine therapy other than tamoxifen for advanced breast cancer. If patients have adjuvant endocrine therapy, they must satisfy as follows: progressed 12 months or more since prior adjuvant endocrine therapy with tamoxifen; or progressed during or after adjuvant endocrine therapy with an aromatase inhibitor.
• Measurable disease or non-measurable disease as defined by RECIST ver.1.1
• Eastern Cooperative Oncology Group (ECOG) PS 0-1
• Adequate organ and marrow function, resolution of all toxic effects of prior therapy or surgical procedures

Exclusion Criteria:

• Prior treatment with any CDK inhibitor, tamoxifen, everolimus, or agent that inhibits the PI3K-mTOR pathway
• Patients with extensive advanced/metastatic, symptomatic visceral disease, or known uncontrolled or symptomatic CNS metastases
• Use of strong or moderate CYP3A4 and/or CYP2D6 inhibitors or inducers
• Major surgery or any anti-cancer therapy within 2 weeks of randomization
• Prior stem cell or bone marrow transplantation